Grapevine

Study addresses challenges in digital animation of coiled hair

We have grown accustomed to seeing many aspects of our everyday world depicted using computer graphics, but some phenomena remain difficult for even the most experienced animators. Hair, specifically the highly coiled hair that is most common to Black characters, remains a notoriously difficult digital challenge.

Part of this problem is the lack of algorithms. Scores of technical papers have been written over the last few decades proposing algorithms for hair, but they have focused on the features most closely associated with white characters: straight or wavy hair. The number of papers written for highly coiled hair (aka Black hair) is virtually zero.

A new paper will be presented at the SIGGRAPH Asia conference in December that is the first to examine the geometric properties of highly coiled hair and propose methods for replicating their unique visual properties (figure 1).

This is the first time a paper on this topic has ever appeared at the conference, which along with its sister conference, SIGGRAPH North America, has existed in various forms for the last 51 years. Considered the premier conference in the field of computer animation, it is attended by leaders in both academia and industry.

For the study, led by Yale computer science professor Theodore Kim, the research team identified a variety of unique visual phenomena that emerge in highly coiled hair. "When you stop thinking of hair as a parabola and instead as a high-frequency helix, lots of interesting things happen," Kim reported.